2 This file is part of GNUnet.
3 Copyright (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
36 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
38 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
40 #if !defined(GNUNET_CULL_LOGGING)
41 #define DUMP_KEYS_TO_STDERR GNUNET_YES
43 #define DUMP_KEYS_TO_STDERR GNUNET_NO
46 /******************************************************************************/
47 /******************************** STRUCTS **********************************/
48 /******************************************************************************/
52 struct CadetTChannel *next;
53 struct CadetTChannel *prev;
54 struct CadetChannel *ch;
59 * Connection list and metadata.
61 struct CadetTConnection
66 struct CadetTConnection *next;
71 struct CadetTConnection *prev;
76 struct CadetConnection *c;
79 * Creation time, to keep oldest connection alive.
81 struct GNUNET_TIME_Absolute created;
84 * Connection throughput, to keep fastest connection alive.
90 * Structure used during a Key eXchange.
92 struct CadetTunnelKXCtx
95 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
96 * end before the key exchange is finished or times out.
98 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
101 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
102 * the other end before the key exchange started.
104 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
107 * Same as @c e_key_old, for the case of two simultaneous KX.
108 * This can happen if cadet decides to start a re-key while the peer has also
109 * started its re-key (due to network delay this is impossible to avoid).
110 * In this case, the key material generated with the peer's old ephemeral
111 * *might* (but doesn't have to) be incorrect.
112 * Since no more than two re-keys can happen simultaneously, this is enough.
114 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
117 * Same as @c d_key_old, for the case described in @c e_key_old2.
119 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
122 * Challenge to send and expect in the PONG.
127 * When the rekey started. One minute after this the new key will be used.
129 struct GNUNET_TIME_Absolute rekey_start_time;
132 * Task for delayed destruction of the Key eXchange context, to allow delayed
133 * messages with the old key to be decrypted successfully.
135 struct GNUNET_SCHEDULER_Task *finish_task;
139 * Encryption systems possible.
141 enum CadetTunnelEncryption
144 * Default Axolotl system.
149 * Fallback OTR-style encryption.
155 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
157 struct CadetTunnelSkippedKey
162 struct CadetTunnelSkippedKey *next;
167 struct CadetTunnelSkippedKey *prev;
170 * When was this key stored (for timeout).
172 struct GNUNET_TIME_Absolute timestamp;
177 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
182 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
186 * Axolotl data, according to https://github.com/trevp/axolotl/wiki
188 struct CadetTunnelAxolotl
191 * A (double linked) list of stored message keys and associated header keys
192 * for "skipped" messages, i.e. messages that have not bee*n
193 * received despite the reception of more recent messages, (head)/
195 struct CadetTunnelSkippedKey *skipped_head;
198 * Skipped messages' keys DLL, tail.
200 struct CadetTunnelSkippedKey *skipped_tail;
203 * Elements in @a skipped_head <-> @a skipped_tail.
208 * 32-byte root key which gets updated by DH ratchet
210 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
213 * 32-byte header key (send)
215 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
218 * 32-byte header key (recv)
220 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
223 * 32-byte next header key (send)
225 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
228 * 32-byte next header key (recv)
230 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
233 * 32-byte chain keys (used for forward-secrecy updating, send)
235 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
238 * 32-byte chain keys (used for forward-secrecy updating, recv)
240 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
243 * ECDH for key exchange (A0 / B0)
245 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
248 * ECDH Ratchet key (send)
250 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
253 * ECDH Ratchet key (recv)
255 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
258 * Message number (reset to 0 with each new ratchet, send)
263 * Message numbers (reset to 0 with each new ratchet, recv)
268 * Previous message numbers (# of msgs sent under prev ratchet)
273 * True (#GNUNET_YES) if the party will send a new ratchet key in next msg.
279 * Struct containing all information regarding a tunnel to a peer.
284 * Endpoint of the tunnel.
286 struct CadetPeer *peer;
289 * Type of encryption used in the tunnel.
291 enum CadetTunnelEncryption enc_type;
296 struct CadetTunnelAxolotl *ax;
299 * State of the tunnel connectivity.
301 enum CadetTunnelCState cstate;
304 * State of the tunnel encryption.
306 enum CadetTunnelEState estate;
309 * Key eXchange context.
311 struct CadetTunnelKXCtx *kx_ctx;
314 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
317 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
320 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
322 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
325 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
327 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
330 * Task to start the rekey process.
332 struct GNUNET_SCHEDULER_Task * rekey_task;
335 * Paths that are actively used to reach the destination peer.
337 struct CadetTConnection *connection_head;
338 struct CadetTConnection *connection_tail;
341 * Next connection number.
346 * Channels inside this tunnel.
348 struct CadetTChannel *channel_head;
349 struct CadetTChannel *channel_tail;
352 * Channel ID for the next created channel.
354 CADET_ChannelNumber next_chid;
357 * Destroy flag: if true, destroy on last message.
359 struct GNUNET_SCHEDULER_Task * destroy_task;
362 * Queued messages, to transmit once tunnel gets connected.
364 struct CadetTunnelDelayed *tq_head;
365 struct CadetTunnelDelayed *tq_tail;
368 * Task to trim connections if too many are present.
370 struct GNUNET_SCHEDULER_Task * trim_connections_task;
373 * Ephemeral message in the queue (to avoid queueing more than one).
375 struct CadetConnectionQueue *ephm_h;
378 * Pong message in the queue.
380 struct CadetConnectionQueue *pong_h;
385 * Struct used to save messages in a non-ready tunnel to send once connected.
387 struct CadetTunnelDelayed
392 struct CadetTunnelDelayed *next;
393 struct CadetTunnelDelayed *prev;
398 struct CadetTunnel *t;
401 * Tunnel queue given to the channel to cancel request. Update on send_queued.
403 struct CadetTunnelQueue *tq;
408 /* struct GNUNET_MessageHeader *msg; */
413 * Handle for messages queued but not yet sent.
415 struct CadetTunnelQueue
418 * Connection queue handle, to cancel if necessary.
420 struct CadetConnectionQueue *cq;
423 * Handle in case message hasn't been given to a connection yet.
425 struct CadetTunnelDelayed *tqd;
428 * Continuation to call once sent.
433 * Closure for @c cont.
440 * Cached Axolotl key with signature.
442 struct CadetAxolotlSignedKey
445 * Information about what is being signed (@a permanent_key).
447 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
450 * Permanent public ECDH key.
452 struct GNUNET_CRYPTO_EcdhePublicKey permanent_key;
455 * An EdDSA signature of the permanent ECDH key with the Peer's ID key.
457 struct GNUNET_CRYPTO_EddsaSignature signature;
461 /******************************************************************************/
462 /******************************* GLOBALS ***********************************/
463 /******************************************************************************/
466 * Global handle to the statistics service.
468 extern struct GNUNET_STATISTICS_Handle *stats;
471 * Local peer own ID (memory efficient handle).
473 extern GNUNET_PEER_Id myid;
476 * Local peer own ID (full value).
478 extern struct GNUNET_PeerIdentity my_full_id;
482 * Don't try to recover tunnels if shutting down.
484 extern int shutting_down;
488 * Set of all tunnels, in order to trigger a new exchange on rekey.
489 * Indexed by peer's ID.
491 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
494 * Default TTL for payload packets.
496 static unsigned long long default_ttl;
500 * Own Peer ID private key.
502 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
504 /******************************** AXOLOTL ************************************/
506 static struct GNUNET_CRYPTO_EcdhePrivateKey *ax_key;
509 * Own Axolotl permanent public key (cache).
511 static struct CadetAxolotlSignedKey ax_identity;
513 /******************************** OTR ***********************************/
517 * Own global OTR ephemeral private key.
519 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
522 * Cached message used to perform a OTR key exchange.
524 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
527 * Task to generate a new OTR ephemeral key.
529 static struct GNUNET_SCHEDULER_Task *rekey_task;
534 static struct GNUNET_TIME_Relative rekey_period;
537 /******************************************************************************/
538 /******************************** STATIC ***********************************/
539 /******************************************************************************/
542 * Get string description for tunnel connectivity state.
544 * @param cs Tunnel state.
546 * @return String representation.
549 cstate2s (enum CadetTunnelCState cs)
555 case CADET_TUNNEL_NEW:
556 return "CADET_TUNNEL_NEW";
557 case CADET_TUNNEL_SEARCHING:
558 return "CADET_TUNNEL_SEARCHING";
559 case CADET_TUNNEL_WAITING:
560 return "CADET_TUNNEL_WAITING";
561 case CADET_TUNNEL_READY:
562 return "CADET_TUNNEL_READY";
563 case CADET_TUNNEL_SHUTDOWN:
564 return "CADET_TUNNEL_SHUTDOWN";
566 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
574 * Get string description for tunnel encryption state.
576 * @param es Tunnel state.
578 * @return String representation.
581 estate2s (enum CadetTunnelEState es)
587 case CADET_TUNNEL_KEY_UNINITIALIZED:
588 return "CADET_TUNNEL_KEY_UNINITIALIZED";
589 case CADET_TUNNEL_KEY_SENT:
590 return "CADET_TUNNEL_KEY_SENT";
591 case CADET_TUNNEL_KEY_PING:
592 return "CADET_TUNNEL_KEY_PING";
593 case CADET_TUNNEL_KEY_OK:
594 return "CADET_TUNNEL_KEY_OK";
595 case CADET_TUNNEL_KEY_REKEY:
596 return "CADET_TUNNEL_KEY_REKEY";
598 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
606 * @brief Check if tunnel is ready to send traffic.
608 * Tunnel must be connected and with encryption correctly set up.
610 * @param t Tunnel to check.
612 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
615 is_ready (struct CadetTunnel *t)
619 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
620 ready = CADET_TUNNEL_READY == t->cstate
621 && (CADET_TUNNEL_KEY_OK == t->estate
622 || CADET_TUNNEL_KEY_REKEY == t->estate);
623 ready = ready || GCT_is_loopback (t);
629 * Check if a key is invalid (NULL pointer or all 0)
631 * @param key Key to check.
633 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
636 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
638 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
643 memset (&null_key, 0, sizeof (null_key));
644 if (0 == memcmp (key, &null_key, sizeof (null_key)))
651 * Ephemeral key message purpose size.
653 * @return Size of the part of the ephemeral key message that must be signed.
656 ephemeral_purpose_size (void)
658 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
659 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
660 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
661 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
662 sizeof (struct GNUNET_PeerIdentity);
667 * Ephemeral key message purpose size.
669 * @return Size of the part of the ephemeral key message that must be signed.
672 ax_purpose_size (void)
674 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
675 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey);
680 * Size of the encrypted part of a ping message.
682 * @return Size of the encrypted part of a ping message.
685 ping_encryption_size (void)
687 return sizeof (uint32_t);
692 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
694 * @param tch Tunnel's channel handle.
696 * @return Amount of messages the channel can still buffer towards the client.
699 get_channel_buffer (const struct CadetTChannel *tch)
703 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
704 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
706 return GCCH_get_buffer (tch->ch, fwd);
711 * Get the channel's allowance status.
713 * @param tch Tunnel's channel handle.
715 * @return #GNUNET_YES if we allowed the client to send data to us.
718 get_channel_allowed (const struct CadetTChannel *tch)
722 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
723 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
725 return GCCH_get_allowed (tch->ch, fwd);
730 * Get the connection's buffer.
732 * @param tc Tunnel's connection handle.
734 * @return Amount of messages the connection can still buffer.
737 get_connection_buffer (const struct CadetTConnection *tc)
741 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
742 fwd = GCC_is_origin (tc->c, GNUNET_YES);
744 return GCC_get_buffer (tc->c, fwd);
749 * Get the connection's allowance.
751 * @param tc Tunnel's connection handle.
753 * @return Amount of messages we have allowed the next peer to send us.
756 get_connection_allowed (const struct CadetTConnection *tc)
760 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
761 fwd = GCC_is_origin (tc->c, GNUNET_YES);
763 return GCC_get_allowed (tc->c, fwd);
768 * Check that a ephemeral key message s well formed and correctly signed.
770 * @param t Tunnel on which the message came.
771 * @param msg The ephemeral key message.
773 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
776 check_ephemeral (struct CadetTunnel *t,
777 const struct GNUNET_CADET_KX_Ephemeral *msg)
779 /* Check message size */
780 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
781 return GNUNET_SYSERR;
783 /* Check signature size */
784 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
785 return GNUNET_SYSERR;
788 if (0 != memcmp (&msg->origin_identity,
789 GCP_get_id (t->peer),
790 sizeof (struct GNUNET_PeerIdentity)))
791 return GNUNET_SYSERR;
793 /* Check signature */
795 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
798 &msg->origin_identity.public_key))
799 return GNUNET_SYSERR;
806 * Select the best key to use for encryption (send), based on KX status.
808 * Normally, return the current key. If there is a KX in progress and the old
809 * key is fresh enough, return the old key.
811 * @param t Tunnel to choose the key from.
813 * @return The optimal key to encrypt/hmac outgoing traffic.
815 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
816 select_key (const struct CadetTunnel *t)
818 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
820 if (NULL != t->kx_ctx
821 && NULL == t->kx_ctx->finish_task)
823 struct GNUNET_TIME_Relative age;
825 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
826 LOG (GNUNET_ERROR_TYPE_DEBUG,
827 " key exchange in progress, started %s ago\n",
828 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
829 // FIXME make duration of old keys configurable
830 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
832 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
833 key = &t->kx_ctx->e_key_old;
837 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
843 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
853 * @param plaintext Content to HMAC.
854 * @param size Size of @c plaintext.
855 * @param iv Initialization vector for the message.
856 * @param key Key to use.
857 * @param hmac[out] Destination to store the HMAC.
860 t_hmac (const void *plaintext, size_t size,
861 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
862 struct GNUNET_CADET_Hash *hmac)
864 static const char ctx[] = "cadet authentication key";
865 struct GNUNET_CRYPTO_AuthKey auth_key;
866 struct GNUNET_HashCode hash;
868 #if DUMP_KEYS_TO_STDERR
869 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
870 GNUNET_h2s ((struct GNUNET_HashCode *) key));
872 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
877 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
878 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
879 memcpy (hmac, &hash, sizeof (*hmac));
884 * Encrypt daforce_newest_keyta with the tunnel key.
886 * @param t Tunnel whose key to use.
887 * @param dst Destination for the encrypted data.
888 * @param src Source of the plaintext. Can overlap with @c dst.
889 * @param size Size of the plaintext.
890 * @param iv Initialization Vector to use.
891 * @param force_newest_key Force the use of the newest key, otherwise
892 * CADET will use the old key when allowed.
893 * This can happen in the case when a KX is going on
894 * and the old one hasn't expired.
897 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
898 size_t size, uint32_t iv, int force_newest_key)
900 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
901 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
904 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
906 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
907 #if DUMP_KEYS_TO_STDERR
908 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
909 GNUNET_h2s ((struct GNUNET_HashCode *) key));
911 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
912 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
913 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
914 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
921 * Generate a new key with a HMAC mechanism from the existing chain key.
923 * @param ax Axolotl context.
924 * @param key[out] Derived key.
925 * @param source Source key material (data to HMAC).
926 * @param len Length of @a source.
929 t_ax_hmac_hash (struct CadetTunnelAxolotl *ax,
930 struct GNUNET_CRYPTO_SymmetricSessionKey *key,
931 void *source, unsigned int len)
933 static const char ctx[] = "axolotl key derivation";
934 struct GNUNET_CRYPTO_AuthKey auth_key;
935 struct GNUNET_HashCode hash;
937 GNUNET_CRYPTO_hmac_derive_key (&auth_key, &ax->CKs,
940 GNUNET_CRYPTO_hmac (&auth_key, source, len, &hash);
941 GNUNET_CRYPTO_kdf (key, sizeof (*key),
943 &hash, sizeof (hash));
948 * Encrypt data with the tunnel key.
950 * @param t Tunnel whose key to use.
951 * @param dst Destination for the encrypted data.
952 * @param src Source of the plaintext. Can overlap with @c dst.
953 * @param size Size of the plaintext.
955 * @return Size of the encrypted data.
958 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
960 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
961 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
962 struct CadetTunnelAxolotl *ax;
965 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
969 if (GNUNET_YES == ax->ratchet_flag)
971 /* Advance ratchet */
974 t_ax_hmac_hash (ax, &MK, "0", 1);
975 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
977 #if DUMP_KEYS_TO_STDERR
978 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
979 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
982 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
984 t_ax_hmac_hash (ax, &ax->CKs, "1", 1);
986 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
993 * Decrypt and verify data with the appropriate tunnel key.
995 * @param key Key to use.
996 * @param dst Destination for the plaintext.
997 * @param src Source of the encrypted data. Can overlap with @c dst.
998 * @param size Size of the encrypted data.
999 * @param iv Initialization Vector to use.
1001 * @return Size of the decrypted data, -1 if an error was encountered.
1004 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1005 void *dst, const void *src, size_t size, uint32_t iv)
1007 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1010 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1011 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1012 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1013 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1014 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1015 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1022 * Decrypt and verify data with the most recent tunnel key.
1024 * @param t Tunnel whose key to use.
1025 * @param dst Destination for the plaintext.
1026 * @param src Source of the encrypted data. Can overlap with @c dst.
1027 * @param size Size of the encrypted data.
1028 * @param iv Initialization Vector to use.
1030 * @return Size of the decrypted data, -1 if an error was encountered.
1033 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1034 size_t size, uint32_t iv)
1038 #if DUMP_KEYS_TO_STDERR
1039 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1040 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1042 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1044 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1045 LOG (GNUNET_ERROR_TYPE_WARNING,
1046 "got data on %s without a valid key\n",
1048 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1052 out_size = decrypt (&t->d_key, dst, src, size, iv);
1059 * Decrypt and verify data with the appropriate tunnel key and verify that the
1060 * data has not been altered since it was sent by the remote peer.
1062 * @param t Tunnel whose key to use.
1063 * @param dst Destination for the plaintext.
1064 * @param src Source of the encrypted data. Can overlap with @c dst.
1065 * @param size Size of the encrypted data.
1066 * @param iv Initialization Vector to use.
1067 * @param msg_hmac HMAC of the message, cannot be NULL.
1069 * @return Size of the decrypted data, -1 if an error was encountered.
1072 t_decrypt_and_validate (struct CadetTunnel *t,
1073 void *dst, const void *src,
1074 size_t size, uint32_t iv,
1075 const struct GNUNET_CADET_Hash *msg_hmac)
1077 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1078 struct GNUNET_CADET_Hash hmac;
1081 /* Try primary (newest) key */
1083 decrypted_size = decrypt (key, dst, src, size, iv);
1084 t_hmac (src, size, iv, key, &hmac);
1085 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1086 return decrypted_size;
1088 /* If no key exchange is going on, we just failed. */
1089 if (NULL == t->kx_ctx)
1091 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1092 "Failed checksum validation on tunnel %s with no KX\n",
1094 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1098 /* Try secondary key, from previous KX period. */
1099 key = &t->kx_ctx->d_key_old;
1100 decrypted_size = decrypt (key, dst, src, size, iv);
1101 t_hmac (src, size, iv, key, &hmac);
1102 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1103 return decrypted_size;
1105 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1106 key = &t->kx_ctx->d_key_old2;
1107 decrypted_size = decrypt (key, dst, src, size, iv);
1108 t_hmac (src, size, iv, key, &hmac);
1109 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1110 return decrypted_size;
1112 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1113 "Failed checksum validation on tunnel %s with KX\n",
1115 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1120 * Decrypt and verify data with the appropriate tunnel key and verify that the
1121 * data has not been altered since it was sent by the remote peer.
1123 * @param t Tunnel whose key to use.
1124 * @param dst Destination for the plaintext.
1125 * @param src Source of the encrypted data. Can overlap with @c dst.
1126 * @param size Size of the encrypted data.
1127 * @param msg_hmac HMAC of the message, cannot be NULL.
1129 * @return Size of the decrypted data, -1 if an error was encountered.
1132 t_ax_decrypt_and_validate (struct CadetTunnel *t,
1133 void *dst, const void *src, size_t size,
1134 const struct GNUNET_CADET_Hash *msg_hmac)
1136 struct CadetTunnelAxolotl *ax;
1151 * Create key material by doing ECDH on the local and remote ephemeral keys.
1153 * @param key_material Where to store the key material.
1154 * @param ephemeral_key Peer's public ephemeral key.
1157 derive_key_material (struct GNUNET_HashCode *key_material,
1158 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
1161 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key,
1171 * Create a symmetic key from the identities of both ends and the key material
1174 * @param key Destination for the generated key.
1175 * @param sender ID of the peer that will encrypt with @c key.
1176 * @param receiver ID of the peer that will decrypt with @c key.
1177 * @param key_material Hash created with ECDH with the ephemeral keys.
1180 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1181 const struct GNUNET_PeerIdentity *sender,
1182 const struct GNUNET_PeerIdentity *receiver,
1183 const struct GNUNET_HashCode *key_material)
1185 const char salt[] = "CADET kx salt";
1187 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1188 salt, sizeof (salt),
1189 key_material, sizeof (struct GNUNET_HashCode),
1190 sender, sizeof (struct GNUNET_PeerIdentity),
1191 receiver, sizeof (struct GNUNET_PeerIdentity),
1197 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1199 * @param t Tunnel for which to create the keys.
1202 create_keys (struct CadetTunnel *t)
1204 struct GNUNET_HashCode km;
1206 derive_key_material (&km, &t->peers_ephemeral_key);
1207 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1208 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1209 #if DUMP_KEYS_TO_STDERR
1210 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1211 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1212 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1213 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1214 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1215 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1216 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1217 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1218 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1224 * Create a new Key eXchange context for the tunnel.
1226 * If the old keys were verified, keep them for old traffic. Create a new KX
1227 * timestamp and a new nonce.
1229 * @param t Tunnel for which to create the KX ctx.
1232 create_kx_ctx (struct CadetTunnel *t)
1234 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1236 if (NULL != t->kx_ctx)
1238 if (NULL != t->kx_ctx->finish_task)
1240 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1241 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1242 t->kx_ctx->finish_task = NULL;
1247 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1248 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1252 if (CADET_TUNNEL_KEY_OK == t->estate)
1254 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1255 t->kx_ctx->d_key_old = t->d_key;
1256 t->kx_ctx->e_key_old = t->e_key;
1259 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1260 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1266 * @brief Finish the Key eXchange and destroy the old keys.
1268 * @param cls Closure (Tunnel for which to finish the KX).
1269 * @param tc Task context.
1272 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1274 struct CadetTunnel *t = cls;
1276 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1278 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1280 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1284 GNUNET_free (t->kx_ctx);
1290 * Destroy a Key eXchange context for the tunnel. This function only schedules
1291 * the destruction, the freeing of the memory (and clearing of old key material)
1292 * happens after a delay!
1294 * @param t Tunnel whose KX ctx to destroy.
1297 destroy_kx_ctx (struct CadetTunnel *t)
1299 struct GNUNET_TIME_Relative delay;
1301 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1304 if (is_key_null (&t->kx_ctx->e_key_old))
1306 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1310 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1311 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1313 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1319 * Pick a connection on which send the next data message.
1321 * @param t Tunnel on which to send the message.
1323 * @return The connection on which to send the next message.
1325 static struct CadetConnection *
1326 tunnel_get_connection (struct CadetTunnel *t)
1328 struct CadetTConnection *iter;
1329 struct CadetConnection *best;
1331 unsigned int lowest_q;
1333 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1335 lowest_q = UINT_MAX;
1336 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1338 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1339 GCC_2s (iter->c), GCC_get_state (iter->c));
1340 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1342 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1343 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1351 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1357 * Callback called when a queued message is sent.
1359 * Calculates the average time and connection packet tracking.
1361 * @param cls Closure (TunnelQueue handle).
1362 * @param c Connection this message was on.
1363 * @param q Connection queue handle (unused).
1364 * @param type Type of message sent.
1365 * @param fwd Was this a FWD going message?
1366 * @param size Size of the message.
1369 tun_message_sent (void *cls,
1370 struct CadetConnection *c,
1371 struct CadetConnectionQueue *q,
1372 uint16_t type, int fwd, size_t size)
1374 struct CadetTunnelQueue *qt = cls;
1375 struct CadetTunnel *t;
1377 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1379 GNUNET_assert (NULL != qt->cont);
1380 t = NULL == c ? NULL : GCC_get_tunnel (c);
1381 qt->cont (qt->cont_cls, t, qt, type, size);
1387 count_queued_data (const struct CadetTunnel *t)
1389 struct CadetTunnelDelayed *iter;
1392 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1399 * Delete a queued message: either was sent or the channel was destroyed
1400 * before the tunnel's key exchange had a chance to finish.
1402 * @param tqd Delayed queue handle.
1405 unqueue_data (struct CadetTunnelDelayed *tqd)
1407 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1413 * Cache a message to be sent once tunnel is online.
1415 * @param t Tunnel to hold the message.
1416 * @param msg Message itself (copy will be made).
1418 static struct CadetTunnelDelayed *
1419 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1421 struct CadetTunnelDelayed *tqd;
1422 uint16_t size = ntohs (msg->size);
1424 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1426 if (GNUNET_YES == is_ready (t))
1432 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1435 memcpy (&tqd[1], msg, size);
1436 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1442 * Sends an already built message on a tunnel, encrypting it and
1443 * choosing the best connection.
1445 * @param message Message to send. Function modifies it.
1446 * @param t Tunnel on which this message is transmitted.
1447 * @param c Connection to use (autoselect if NULL).
1448 * @param force Force the tunnel to take the message (buffer overfill).
1449 * @param cont Continuation to call once message is really sent.
1450 * @param cont_cls Closure for @c cont.
1451 * @param existing_q In case this a transmission of previously queued data,
1452 * this should be TunnelQueue given to the client.
1455 * @return Handle to cancel message.
1456 * NULL if @c cont is NULL or an error happens and message is dropped.
1458 static struct CadetTunnelQueue *
1459 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1460 struct CadetTunnel *t, struct CadetConnection *c,
1461 int force, GCT_sent cont, void *cont_cls,
1462 struct CadetTunnelQueue *existing_q)
1464 struct CadetTunnelQueue *tq;
1465 struct GNUNET_CADET_Encrypted *msg;
1466 size_t size = ntohs (message->size);
1467 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1474 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1476 if (GNUNET_NO == is_ready (t))
1478 struct CadetTunnelDelayed *tqd;
1479 /* A non null existing_q indicates sending of queued data.
1480 * Should only happen after tunnel becomes ready.
1482 GNUNET_assert (NULL == existing_q);
1483 tqd = queue_data (t, message);
1486 tq = GNUNET_new (struct CadetTunnelQueue);
1490 tq->cont_cls = cont_cls;
1494 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1496 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1497 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1498 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1501 if (CADET_Axolotl == t->enc_type)
1502 esize = t_ax_encrypt (t, &msg[1], message, size);
1504 esize = t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO);
1505 GNUNET_assert (esize == size);
1506 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1507 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1510 c = tunnel_get_connection (t);
1513 /* Why is tunnel 'ready'? Should have been queued! */
1514 if (NULL != t->destroy_task)
1517 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1519 return NULL; /* Drop... */
1523 type = ntohs (message->type);
1526 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1527 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1528 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1529 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1531 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1533 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1534 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1535 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1536 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1537 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1538 msg->cid = *GCC_get_id (c);
1539 msg->ttl = htonl (default_ttl);
1543 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1545 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1547 fwd = GCC_is_origin (c, GNUNET_YES);
1551 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1552 fwd, force, NULL, NULL));
1555 if (NULL == existing_q)
1557 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1564 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1565 &tun_message_sent, tq);
1566 GNUNET_assert (NULL != tq->cq);
1568 tq->cont_cls = cont_cls;
1575 * Send all cached messages that we can, tunnel is online.
1577 * @param t Tunnel that holds the messages. Cannot be loopback.
1580 send_queued_data (struct CadetTunnel *t)
1582 struct CadetTunnelDelayed *tqd;
1583 struct CadetTunnelDelayed *next;
1586 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1588 if (GCT_is_loopback (t))
1594 if (GNUNET_NO == is_ready (t))
1596 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1597 estate2s (t->estate), cstate2s (t->cstate));
1601 room = GCT_get_connections_buffer (t);
1602 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1603 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1604 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1606 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1609 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1610 tqd->t, NULL, GNUNET_YES,
1611 NULL != tqd->tq ? tqd->tq->cont : NULL,
1612 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1616 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1621 * Callback called when a queued message is sent.
1623 * @param cls Closure.
1624 * @param c Connection this message was on.
1625 * @param type Type of message sent.
1626 * @param fwd Was this a FWD going message?
1627 * @param size Size of the message.
1630 ephm_sent (void *cls,
1631 struct CadetConnection *c,
1632 struct CadetConnectionQueue *q,
1633 uint16_t type, int fwd, size_t size)
1635 struct CadetTunnel *t = cls;
1636 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
1641 * Callback called when a queued message is sent.
1643 * @param cls Closure.
1644 * @param c Connection this message was on.
1645 * @param type Type of message sent.
1646 * @param fwd Was this a FWD going message?
1647 * @param size Size of the message.
1650 pong_sent (void *cls,
1651 struct CadetConnection *c,
1652 struct CadetConnectionQueue *q,
1653 uint16_t type, int fwd, size_t size)
1655 struct CadetTunnel *t = cls;
1656 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
1662 * Sends key exchange message on a tunnel, choosing the best connection.
1663 * Should not be called on loopback tunnels.
1665 * @param t Tunnel on which this message is transmitted.
1666 * @param message Message to send. Function modifies it.
1668 * @return Handle to the message in the connection queue.
1670 static struct CadetConnectionQueue *
1671 send_kx (struct CadetTunnel *t,
1672 const struct GNUNET_MessageHeader *message)
1674 struct CadetConnection *c;
1675 struct GNUNET_CADET_KX *msg;
1676 size_t size = ntohs (message->size);
1677 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1682 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1684 /* Avoid loopback. */
1685 if (GCT_is_loopback (t))
1690 type = ntohs (message->type);
1692 /* Even if tunnel is "being destroyed", send anyway.
1693 * Could be a response to a rekey initiated by remote peer,
1694 * who is trying to create a new channel!
1697 /* Must have a connection, or be looking for one. */
1698 if (NULL == t->connection_head)
1700 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
1701 if (CADET_TUNNEL_SEARCHING != t->cstate)
1704 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1705 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1710 msg = (struct GNUNET_CADET_KX *) cbuf;
1711 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1712 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1713 c = tunnel_get_connection (t);
1716 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
1719 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1725 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1726 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
1727 GNUNET_assert (NULL == t->ephm_h);
1730 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1731 GNUNET_assert (NULL == t->pong_h);
1736 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
1739 memcpy (&msg[1], message, size);
1741 fwd = GCC_is_origin (c, GNUNET_YES);
1743 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
1750 * Send the ephemeral key on a tunnel.
1752 * @param t Tunnel on which to send the key.
1755 send_ephemeral (struct CadetTunnel *t)
1757 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1758 if (NULL != t->ephm_h)
1760 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1764 otr_kx_msg.sender_status = htonl (t->estate);
1765 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1766 otr_kx_msg.nonce = t->kx_ctx->challenge;
1767 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
1768 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
1769 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
1770 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
1771 t->ephm_h = send_kx (t, &otr_kx_msg.header);
1776 * Send a pong message on a tunnel.
1778 * @param t Tunnel on which to send the pong.
1779 * @param challenge Value sent in the ping that we have to send back.
1782 send_pong (struct CadetTunnel *t, uint32_t challenge)
1784 struct GNUNET_CADET_KX_Pong msg;
1786 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1787 if (NULL != t->pong_h)
1789 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
1792 msg.header.size = htons (sizeof (msg));
1793 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1794 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1795 msg.nonce = challenge;
1796 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1797 t_encrypt (t, &msg.nonce, &msg.nonce,
1798 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1799 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1801 t->pong_h = send_kx (t, &msg.header);
1806 * Initiate a rekey with the remote peer.
1808 * @param cls Closure (tunnel).
1809 * @param tc TaskContext.
1812 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1814 struct CadetTunnel *t = cls;
1816 t->rekey_task = NULL;
1818 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1819 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1822 GNUNET_assert (NULL != t->kx_ctx);
1823 struct GNUNET_TIME_Relative duration;
1825 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1826 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1827 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1829 // FIXME make duration of old keys configurable
1830 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1832 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1833 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1834 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1841 case CADET_TUNNEL_KEY_UNINITIALIZED:
1842 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1845 case CADET_TUNNEL_KEY_SENT:
1848 case CADET_TUNNEL_KEY_OK:
1850 * - state should have changed during rekey_iterator
1851 * - task should have been canceled at pong_handle
1854 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1857 case CADET_TUNNEL_KEY_PING:
1858 case CADET_TUNNEL_KEY_REKEY:
1862 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1865 // FIXME exponential backoff
1866 struct GNUNET_TIME_Relative delay;
1868 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1869 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1870 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1871 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1872 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1877 * Our ephemeral key has changed, create new session key on all tunnels.
1879 * Each tunnel will start the Key Exchange with a random delay between
1880 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1881 * per second, on average.
1883 * @param cls Closure (size of the hashmap).
1884 * @param key Current public key.
1885 * @param value Value in the hash map (tunnel).
1887 * @return #GNUNET_YES, so we should continue to iterate,
1890 rekey_iterator (void *cls,
1891 const struct GNUNET_PeerIdentity *key,
1894 struct CadetTunnel *t = value;
1895 struct GNUNET_TIME_Relative delay;
1896 long n = (long) cls;
1899 if (NULL != t->rekey_task)
1902 if (GNUNET_YES == GCT_is_loopback (t))
1905 if (CADET_OTR != t->enc_type)
1908 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1909 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1910 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1912 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1919 * Create a new ephemeral key and key message, schedule next rekeying.
1921 * @param cls Closure (unused).
1922 * @param tc TaskContext.
1925 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1927 struct GNUNET_TIME_Absolute time;
1932 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1935 GNUNET_free_non_null (otr_ephemeral_key);
1936 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1938 time = GNUNET_TIME_absolute_get ();
1939 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1940 time = GNUNET_TIME_absolute_add (time, rekey_period);
1941 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1942 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1943 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
1944 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
1945 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1947 GNUNET_assert (GNUNET_OK ==
1948 GNUNET_CRYPTO_eddsa_sign (id_key,
1949 &otr_kx_msg.purpose,
1950 &otr_kx_msg.signature));
1952 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1953 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1955 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
1956 &global_otr_rekey, NULL);
1961 * Called only on shutdown, destroy every tunnel.
1963 * @param cls Closure (unused).
1964 * @param key Current public key.
1965 * @param value Value in the hash map (tunnel).
1967 * @return #GNUNET_YES, so we should continue to iterate,
1970 destroy_iterator (void *cls,
1971 const struct GNUNET_PeerIdentity *key,
1974 struct CadetTunnel *t = value;
1976 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1983 * Notify remote peer that we don't know a channel he is talking about,
1984 * probably CHANNEL_DESTROY was missed.
1986 * @param t Tunnel on which to notify.
1987 * @param gid ID of the channel.
1990 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1992 struct GNUNET_CADET_ChannelManage msg;
1994 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1995 msg.header.size = htons (sizeof (msg));
1996 msg.chid = htonl (gid);
1998 LOG (GNUNET_ERROR_TYPE_DEBUG,
1999 "WARNING destroying unknown channel %u on tunnel %s\n",
2001 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2006 * Demultiplex data per channel and call appropriate channel handler.
2008 * @param t Tunnel on which the data came.
2009 * @param msg Data message.
2010 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2011 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2012 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2013 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2016 handle_data (struct CadetTunnel *t,
2017 const struct GNUNET_CADET_Data *msg,
2020 struct CadetChannel *ch;
2024 size = ntohs (msg->header.size);
2026 sizeof (struct GNUNET_CADET_Data) +
2027 sizeof (struct GNUNET_MessageHeader))
2032 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2033 GC_m2s (ntohs (msg[1].header.type)));
2036 ch = GCT_get_channel (t, ntohl (msg->chid));
2039 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2041 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2043 send_channel_destroy (t, ntohl (msg->chid));
2047 GCCH_handle_data (ch, msg, fwd);
2052 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2054 * @param t Tunnel on which the DATA ACK came.
2055 * @param msg DATA ACK message.
2056 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2057 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2058 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2059 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2062 handle_data_ack (struct CadetTunnel *t,
2063 const struct GNUNET_CADET_DataACK *msg,
2066 struct CadetChannel *ch;
2070 size = ntohs (msg->header.size);
2071 if (size != sizeof (struct GNUNET_CADET_DataACK))
2078 ch = GCT_get_channel (t, ntohl (msg->chid));
2081 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2083 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2088 GCCH_handle_data_ack (ch, msg, fwd);
2093 * Handle channel create.
2095 * @param t Tunnel on which the data came.
2096 * @param msg Data message.
2099 handle_ch_create (struct CadetTunnel *t,
2100 const struct GNUNET_CADET_ChannelCreate *msg)
2102 struct CadetChannel *ch;
2106 size = ntohs (msg->header.size);
2107 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2114 ch = GCT_get_channel (t, ntohl (msg->chid));
2115 if (NULL != ch && ! GCT_is_loopback (t))
2117 /* Probably a retransmission, safe to ignore */
2118 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2120 ch = GCCH_handle_create (t, msg);
2122 GCT_add_channel (t, ch);
2128 * Handle channel NACK: check correctness and call channel handler for NACKs.
2130 * @param t Tunnel on which the NACK came.
2131 * @param msg NACK message.
2134 handle_ch_nack (struct CadetTunnel *t,
2135 const struct GNUNET_CADET_ChannelManage *msg)
2137 struct CadetChannel *ch;
2141 size = ntohs (msg->header.size);
2142 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2149 ch = GCT_get_channel (t, ntohl (msg->chid));
2152 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2154 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2159 GCCH_handle_nack (ch);
2164 * Handle a CHANNEL ACK (SYNACK/ACK).
2166 * @param t Tunnel on which the CHANNEL ACK came.
2167 * @param msg CHANNEL ACK message.
2168 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2169 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2170 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2171 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2174 handle_ch_ack (struct CadetTunnel *t,
2175 const struct GNUNET_CADET_ChannelManage *msg,
2178 struct CadetChannel *ch;
2182 size = ntohs (msg->header.size);
2183 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2190 ch = GCT_get_channel (t, ntohl (msg->chid));
2193 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2195 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2200 GCCH_handle_ack (ch, msg, fwd);
2205 * Handle a channel destruction message.
2207 * @param t Tunnel on which the message came.
2208 * @param msg Channel destroy message.
2209 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2210 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2211 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2212 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2215 handle_ch_destroy (struct CadetTunnel *t,
2216 const struct GNUNET_CADET_ChannelManage *msg,
2219 struct CadetChannel *ch;
2223 size = ntohs (msg->header.size);
2224 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2231 ch = GCT_get_channel (t, ntohl (msg->chid));
2234 /* Probably a retransmission, safe to ignore */
2238 GCCH_handle_destroy (ch, msg, fwd);
2243 * Create a new Axolotl ephemeral (ratchet) key.
2248 new_ephemeral (struct CadetTunnel *t)
2250 GNUNET_free_non_null (t->ax->DHRs);
2251 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
2256 * Free Axolotl data.
2261 destroy_ax (struct CadetTunnel *t)
2266 GNUNET_free_non_null (t->ax->DHRs);
2267 GNUNET_free_non_null (t->ax->kx_0);
2269 GNUNET_free (t->ax);
2276 * The peer's ephemeral key has changed: update the symmetrical keys.
2278 * @param t Tunnel this message came on.
2279 * @param msg Key eXchange message.
2282 handle_ephemeral (struct CadetTunnel *t,
2283 const struct GNUNET_CADET_KX_Ephemeral *msg)
2285 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2287 if (GNUNET_OK != check_ephemeral (t, msg))
2289 GNUNET_break_op (0);
2293 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2297 t->enc_type = CADET_OTR;
2298 if (NULL != t->rekey_task)
2299 GNUNET_SCHEDULER_cancel (t->rekey_task);
2301 rekey_tunnel (t, NULL);
2305 * If the key is different from what we know, derive the new E/D keys.
2306 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2308 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2309 sizeof (msg->ephemeral_key)))
2311 #if DUMP_KEYS_TO_STDERR
2312 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2313 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2314 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2315 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2317 t->peers_ephemeral_key = msg->ephemeral_key;
2321 if (CADET_TUNNEL_KEY_OK == t->estate)
2323 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2325 if (NULL != t->rekey_task)
2326 GNUNET_SCHEDULER_cancel (t->rekey_task);
2327 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2329 if (CADET_TUNNEL_KEY_SENT == t->estate)
2331 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2333 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2336 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2340 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2341 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2342 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2343 send_pong (t, nonce);
2349 * Peer has answer to our challenge.
2350 * If answer is successful, consider the key exchange finished and clean
2351 * up all related state.
2353 * @param t Tunnel this message came on.
2354 * @param msg Key eXchange Pong message.
2357 handle_pong (struct CadetTunnel *t, const struct GNUNET_CADET_KX_Pong *msg)
2361 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2362 if (NULL == t->rekey_task)
2364 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2367 if (NULL == t->kx_ctx)
2369 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2373 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2374 if (challenge != t->kx_ctx->challenge)
2376 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2377 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2378 challenge, msg->nonce, t->kx_ctx->challenge);
2382 GNUNET_SCHEDULER_cancel (t->rekey_task);
2383 t->rekey_task = NULL;
2385 /* Don't free the old keys right away, but after a delay.
2386 * Rationale: the KX could have happened over a very fast connection,
2387 * with payload traffic still signed with the old key stuck in a slower
2389 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2393 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2398 * Handle Axolotl handshake.
2400 * @param t Tunnel this message came on.
2401 * @param msg Key eXchange Pong message.
2404 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2406 struct CadetTunnelAxolotl *ax;
2407 struct GNUNET_HashCode key_material[3];
2408 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2409 const struct GNUNET_CRYPTO_EcdhePublicKey *pub;
2410 const struct GNUNET_CRYPTO_EcdhePrivateKey *priv;
2411 const char salt[] = "CADET Axolotl salt";
2412 const struct GNUNET_PeerIdentity *pid;
2415 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2419 /* Something is wrong if ax is NULL. Whose fault it is? */
2420 GNUNET_break_op (CADET_OTR == t->enc_type);
2421 GNUNET_break (CADET_Axolotl == t->enc_type);
2425 if (GNUNET_OK != GCP_check_key (t->peer, &msg->permanent_key,
2426 &msg->purpose, &msg->signature))
2428 GNUNET_break_op (0);
2432 pid = GCT_get_destination (t);
2433 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2434 am_I_alice = GNUNET_YES;
2435 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2436 am_I_alice = GNUNET_NO;
2439 GNUNET_break_op (0);
2443 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2446 ax->DHRr = msg->ratchet_key;
2449 if (GNUNET_YES == am_I_alice)
2451 priv = ax_key; /* A */
2452 pub = &msg->ephemeral_key; /* B0 */
2456 priv = ax->kx_0; /* B0 */
2457 pub = &msg->permanent_key; /* A */
2459 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[0]);
2462 if (GNUNET_YES == am_I_alice)
2464 priv = ax->kx_0; /* A0 */
2465 pub = &msg->permanent_key; /* B */
2469 priv = ax_key; /* B */
2470 pub = &msg->ephemeral_key; /* A0 */
2472 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[1]);
2475 priv = ax->kx_0; /* A0 or B0 */
2476 pub = &msg->ephemeral_key; /* B0 or A0 */
2477 GNUNET_CRYPTO_ecc_ecdh (priv, pub, &key_material[2]);
2479 #if DUMP_KEYS_TO_STDERR
2482 for (i = 0; i < 3; i++)
2483 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2484 i, GNUNET_h2s (&key_material[i]));
2489 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2490 salt, sizeof (salt),
2491 &key_material, sizeof (key_material), NULL);
2494 if (GNUNET_YES == am_I_alice)
2500 ax->ratchet_flag = GNUNET_YES;
2508 ax->ratchet_flag = GNUNET_NO;
2510 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2515 * Demultiplex by message type and call appropriate handler for a message
2516 * towards a channel of a local tunnel.
2518 * @param t Tunnel this message came on.
2519 * @param msgh Message header.
2520 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2521 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2522 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2523 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2526 handle_decrypted (struct CadetTunnel *t,
2527 const struct GNUNET_MessageHeader *msgh,
2532 type = ntohs (msgh->type);
2533 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2537 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2538 /* Do nothing, connection aleady got updated. */
2539 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2542 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2543 /* Don't send hop ACK, wait for client to ACK */
2544 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2547 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2548 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2551 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2552 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
2555 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2556 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
2559 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2560 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2563 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2564 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
2568 GNUNET_break_op (0);
2569 LOG (GNUNET_ERROR_TYPE_WARNING,
2570 "end-to-end message not known (%u)\n",
2571 ntohs (msgh->type));
2572 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2576 /******************************************************************************/
2577 /******************************** API ***********************************/
2578 /******************************************************************************/
2580 * Decrypt old format and demultiplex by message type. Call appropriate handler
2581 * for a message towards a channel of a local tunnel.
2583 * @param t Tunnel this message came on.
2584 * @param msg Message header.
2587 GCT_handle_encrypted (struct CadetTunnel *t,
2588 const struct GNUNET_MessageHeader *msg)
2590 size_t size = ntohs (msg->size);
2591 size_t payload_size;
2594 uint16_t type = ntohs (msg->type);
2595 struct GNUNET_MessageHeader *msgh;
2598 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2600 const struct GNUNET_CADET_Encrypted *emsg;
2602 emsg = (struct GNUNET_CADET_Encrypted *) msg;
2603 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2604 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
2605 emsg->iv, &emsg->hmac);
2607 else if (GNUNET_MESSAGE_TYPE_CADET_AX == type)
2609 const struct GNUNET_CADET_AX *emsg;
2611 emsg = (struct GNUNET_CADET_AX *) msg;
2612 payload_size = size - sizeof (struct GNUNET_CADET_AX);
2613 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, &emsg[1],
2614 payload_size, &emsg->hmac);
2617 if (-1 == decrypted_size)
2619 GNUNET_break_op (0);
2624 while (off < decrypted_size)
2628 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2629 msize = ntohs (msgh->size);
2630 if (msize < sizeof (struct GNUNET_MessageHeader))
2632 GNUNET_break_op (0);
2635 handle_decrypted (t, msgh, GNUNET_SYSERR);
2642 * Demultiplex an encapsulated KX message by message type.
2644 * @param t Tunnel on which the message came.
2645 * @param message Payload of KX message.
2648 GCT_handle_kx (struct CadetTunnel *t,
2649 const struct GNUNET_MessageHeader *message)
2653 type = ntohs (message->type);
2654 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
2657 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2658 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
2661 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2662 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
2665 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2666 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
2670 GNUNET_break_op (0);
2671 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
2676 * Initialize the tunnel subsystem.
2678 * @param c Configuration handle.
2679 * @param key ECC private key, to derive all other keys and do crypto.
2682 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2683 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2685 int expected_overhead;
2687 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2689 expected_overhead = 0;
2690 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
2691 expected_overhead += sizeof (struct GNUNET_CADET_Data);
2692 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
2693 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2696 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2699 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2700 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2704 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2707 rekey_period = GNUNET_TIME_UNIT_DAYS;
2712 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
2713 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2714 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2715 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2716 otr_kx_msg.origin_identity = my_full_id;
2717 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
2719 ax_key = GNUNET_CRYPTO_ecdhe_key_create ();
2720 GNUNET_CRYPTO_ecdhe_key_get_public (ax_key, &ax_identity.permanent_key);
2721 ax_identity.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_AXKX);
2722 ax_identity.purpose.size = htonl (ax_purpose_size ());
2723 GNUNET_assert (GNUNET_OK ==
2724 GNUNET_CRYPTO_eddsa_sign (id_key,
2725 &ax_identity.purpose,
2726 &ax_identity.signature));
2728 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2733 * Shut down the tunnel subsystem.
2738 if (NULL != rekey_task)
2740 GNUNET_SCHEDULER_cancel (rekey_task);
2743 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2744 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2745 GNUNET_free (ax_key);
2752 * @param destination Peer this tunnel is towards.
2754 struct CadetTunnel *
2755 GCT_new (struct CadetPeer *destination)
2757 struct CadetTunnel *t;
2759 t = GNUNET_new (struct CadetTunnel);
2761 t->peer = destination;
2764 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2765 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2771 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
2773 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
2779 * Change the tunnel's connection state.
2781 * @param t Tunnel whose connection state to change.
2782 * @param cstate New connection state.
2785 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2789 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2790 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2791 if (myid != GCP_get_short_id (t->peer) &&
2792 CADET_TUNNEL_READY != t->cstate &&
2793 CADET_TUNNEL_READY == cstate)
2796 if (CADET_TUNNEL_KEY_OK == t->estate)
2798 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2799 send_queued_data (t);
2801 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2803 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
2808 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
2813 if (CADET_TUNNEL_READY == cstate
2814 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2816 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2817 GCP_stop_search (t->peer);
2823 * Change the tunnel encryption state.
2825 * @param t Tunnel whose encryption state to change, or NULL.
2826 * @param state New encryption state.
2829 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2831 enum CadetTunnelEState old;
2838 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2839 GCP_2s (t->peer), estate2s (old));
2840 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2841 GCP_2s (t->peer), estate2s (t->estate));
2843 /* Send queued data if enc state changes to OK */
2844 if (myid != GCP_get_short_id (t->peer) &&
2845 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2847 send_queued_data (t);
2853 * @brief Check if tunnel has too many connections, and remove one if necessary.
2855 * Currently this means the newest connection, unless it is a direct one.
2856 * Implemented as a task to avoid freeing a connection that is in the middle
2857 * of being created/processed.
2859 * @param cls Closure (Tunnel to check).
2860 * @param tc Task context.
2863 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2865 struct CadetTunnel *t = cls;
2867 t->trim_connections_task = NULL;
2869 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2872 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2874 struct CadetTConnection *iter;
2875 struct CadetTConnection *c;
2877 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2879 if ((iter->created.abs_value_us > c->created.abs_value_us)
2880 && GNUNET_NO == GCC_is_direct (iter->c))
2887 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2889 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2902 * Add a connection to a tunnel.
2905 * @param c Connection.
2908 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2910 struct CadetTConnection *aux;
2912 GNUNET_assert (NULL != c);
2914 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2915 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2916 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2920 aux = GNUNET_new (struct CadetTConnection);
2922 aux->created = GNUNET_TIME_absolute_get ();
2924 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2926 if (CADET_TUNNEL_SEARCHING == t->cstate)
2927 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2929 if (NULL != t->trim_connections_task)
2930 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2935 * Remove a connection from a tunnel.
2938 * @param c Connection.
2941 GCT_remove_connection (struct CadetTunnel *t,
2942 struct CadetConnection *c)
2944 struct CadetTConnection *aux;
2945 struct CadetTConnection *next;
2948 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2949 GCC_2s (c), GCT_2s (t));
2950 for (aux = t->connection_head; aux != NULL; aux = next)
2955 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2960 conns = GCT_count_connections (t);
2962 && NULL == t->destroy_task
2963 && CADET_TUNNEL_SHUTDOWN != t->cstate
2964 && GNUNET_NO == shutting_down)
2966 if (0 == GCT_count_any_connections (t))
2967 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2969 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2972 /* Start new connections if needed */
2973 if (CONNECTIONS_PER_TUNNEL > conns
2974 && NULL == t->destroy_task
2975 && CADET_TUNNEL_SHUTDOWN != t->cstate
2976 && GNUNET_NO == shutting_down)
2978 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2979 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2983 /* If not marked as ready, no change is needed */
2984 if (CADET_TUNNEL_READY != t->cstate)
2987 /* Check if any connection is ready to maintain cstate */
2988 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2989 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2995 * Add a channel to a tunnel.
2998 * @param ch Channel.
3001 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3003 struct CadetTChannel *aux;
3005 GNUNET_assert (NULL != ch);
3007 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3009 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3011 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3016 aux = GNUNET_new (struct CadetTChannel);
3018 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3019 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3021 if (NULL != t->destroy_task)
3023 GNUNET_SCHEDULER_cancel (t->destroy_task);
3024 t->destroy_task = NULL;
3025 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3031 * Remove a channel from a tunnel.
3034 * @param ch Channel.
3037 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3039 struct CadetTChannel *aux;
3041 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3042 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3046 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3047 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3056 * Search for a channel by global ID.
3058 * @param t Tunnel containing the channel.
3059 * @param chid Public channel number.
3061 * @return channel handler, NULL if doesn't exist
3063 struct CadetChannel *
3064 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3066 struct CadetTChannel *iter;
3071 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3073 if (GCCH_get_id (iter->ch) == chid)
3077 return NULL == iter ? NULL : iter->ch;
3082 * @brief Destroy a tunnel and free all resources.
3084 * Should only be called a while after the tunnel has been marked as destroyed,
3085 * in case there is a new channel added to the same peer shortly after marking
3086 * the tunnel. This way we avoid a new public key handshake.
3088 * @param cls Closure (tunnel to destroy).
3089 * @param tc Task context.
3092 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3094 struct CadetTunnel *t = cls;
3095 struct CadetTConnection *iter;
3097 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3098 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3100 LOG (GNUNET_ERROR_TYPE_WARNING,
3101 "Not destroying tunnel, due to shutdown. "
3102 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3105 t->destroy_task = NULL;
3106 t->cstate = CADET_TUNNEL_SHUTDOWN;
3108 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3110 GCC_send_destroy (iter->c);
3117 * Tunnel is empty: destroy it.
3119 * Notifies all connections about the destruction.
3121 * @param t Tunnel to destroy.
3124 GCT_destroy_empty (struct CadetTunnel *t)
3126 if (GNUNET_YES == shutting_down)
3127 return; /* Will be destroyed immediately anyway */
3129 if (NULL != t->destroy_task)
3131 LOG (GNUNET_ERROR_TYPE_WARNING,
3132 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3134 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3136 /* should never happen, tunnel can only become empty once, and the
3137 * task identifier should be NO_TASK (cleaned when the tunnel was created
3138 * or became un-empty)
3143 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3146 // FIXME make delay a config option
3147 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3148 &delayed_destroy, t);
3149 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3150 t, t->destroy_task);
3155 * Destroy tunnel if empty (no more channels).
3157 * @param t Tunnel to destroy if empty.
3160 GCT_destroy_if_empty (struct CadetTunnel *t)
3162 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3163 if (0 < GCT_count_channels (t))
3166 GCT_destroy_empty (t);
3171 * Destroy the tunnel.
3173 * This function does not generate any warning traffic to clients or peers.
3176 * Cancel messages belonging to this tunnel queued to neighbors.
3177 * Free any allocated resources linked to the tunnel.
3179 * @param t The tunnel to destroy.
3182 GCT_destroy (struct CadetTunnel *t)
3184 struct CadetTConnection *iter_c;
3185 struct CadetTConnection *next_c;
3186 struct CadetTChannel *iter_ch;
3187 struct CadetTChannel *next_ch;
3192 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3194 GNUNET_break (GNUNET_YES ==
3195 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3196 GCP_get_id (t->peer), t));
3198 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3200 next_c = iter_c->next;
3201 GCC_destroy (iter_c->c);
3203 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3205 next_ch = iter_ch->next;
3206 GCCH_destroy (iter_ch->ch);
3207 /* Should only happen on shutdown, but it's ok. */
3210 if (NULL != t->destroy_task)
3212 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3213 GNUNET_SCHEDULER_cancel (t->destroy_task);
3214 t->destroy_task = NULL;
3217 if (NULL != t->trim_connections_task)
3219 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3220 t->trim_connections_task);
3221 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3222 t->trim_connections_task = NULL;
3225 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3226 GCP_set_tunnel (t->peer, NULL);
3228 if (NULL != t->rekey_task)
3230 GNUNET_SCHEDULER_cancel (t->rekey_task);
3231 t->rekey_task = NULL;
3233 if (NULL != t->kx_ctx)
3235 if (NULL != t->kx_ctx->finish_task)
3236 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3237 GNUNET_free (t->kx_ctx);
3248 * @brief Use the given path for the tunnel.
3249 * Update the next and prev hops (and RCs).
3250 * (Re)start the path refresh in case the tunnel is locally owned.
3252 * @param t Tunnel to update.
3253 * @param p Path to use.
3255 * @return Connection created.
3257 struct CadetConnection *
3258 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3260 struct CadetConnection *c;
3261 struct GNUNET_CADET_Hash cid;
3262 unsigned int own_pos;
3264 if (NULL == t || NULL == p)
3270 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3276 for (own_pos = 0; own_pos < p->length; own_pos++)
3278 if (p->peers[own_pos] == myid)
3281 if (own_pos >= p->length)
3283 GNUNET_break_op (0);
3287 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3288 c = GCC_new (&cid, t, p, own_pos);
3291 /* Path was flawed */
3294 GCT_add_connection (t, c);
3300 * Count all created connections of a tunnel. Not necessarily ready connections!
3302 * @param t Tunnel on which to count.
3304 * @return Number of connections created, either being established or ready.
3307 GCT_count_any_connections (struct CadetTunnel *t)
3309 struct CadetTConnection *iter;
3315 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3323 * Count established (ready) connections of a tunnel.
3325 * @param t Tunnel on which to count.
3327 * @return Number of connections.
3330 GCT_count_connections (struct CadetTunnel *t)
3332 struct CadetTConnection *iter;
3338 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3339 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3347 * Count channels of a tunnel.
3349 * @param t Tunnel on which to count.
3351 * @return Number of channels.
3354 GCT_count_channels (struct CadetTunnel *t)
3356 struct CadetTChannel *iter;
3359 for (count = 0, iter = t->channel_head;
3361 iter = iter->next, count++) /* skip */;
3368 * Get the connectivity state of a tunnel.
3372 * @return Tunnel's connectivity state.
3374 enum CadetTunnelCState
3375 GCT_get_cstate (struct CadetTunnel *t)
3380 return (enum CadetTunnelCState) -1;
3387 * Get the encryption state of a tunnel.
3391 * @return Tunnel's encryption state.
3393 enum CadetTunnelEState
3394 GCT_get_estate (struct CadetTunnel *t)
3399 return (enum CadetTunnelEState) -1;
3405 * Get the maximum buffer space for a tunnel towards a local client.
3409 * @return Biggest buffer space offered by any channel in the tunnel.
3412 GCT_get_channels_buffer (struct CadetTunnel *t)
3414 struct CadetTChannel *iter;
3415 unsigned int buffer;
3416 unsigned int ch_buf;
3418 if (NULL == t->channel_head)
3420 /* Probably getting buffer for a channel create/handshake. */
3421 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3426 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3428 ch_buf = get_channel_buffer (iter);
3429 if (ch_buf > buffer)
3437 * Get the total buffer space for a tunnel for P2P traffic.
3441 * @return Buffer space offered by all connections in the tunnel.
3444 GCT_get_connections_buffer (struct CadetTunnel *t)
3446 struct CadetTConnection *iter;
3447 unsigned int buffer;
3449 if (GNUNET_NO == is_ready (t))
3451 if (count_queued_data (t) > 3)
3458 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3460 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3464 buffer += get_connection_buffer (iter);
3472 * Get the tunnel's destination.
3476 * @return ID of the destination peer.
3478 const struct GNUNET_PeerIdentity *
3479 GCT_get_destination (struct CadetTunnel *t)
3481 return GCP_get_id (t->peer);
3486 * Get the tunnel's next free global channel ID.
3490 * @return GID of a channel free to use.
3493 GCT_get_next_chid (struct CadetTunnel *t)
3495 CADET_ChannelNumber chid;
3496 CADET_ChannelNumber mask;
3499 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3500 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3501 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3503 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3508 t->next_chid |= mask;
3510 while (NULL != GCT_get_channel (t, t->next_chid))
3512 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3513 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3514 t->next_chid |= mask;
3516 chid = t->next_chid;
3517 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3518 t->next_chid |= mask;
3525 * Send ACK on one or more channels due to buffer in connections.
3527 * @param t Channel which has some free buffer space.
3530 GCT_unchoke_channels (struct CadetTunnel *t)
3532 struct CadetTChannel *iter;
3533 unsigned int buffer;
3534 unsigned int channels = GCT_count_channels (t);
3535 unsigned int choked_n;
3536 struct CadetChannel *choked[channels];
3538 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
3539 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
3540 if (NULL != t->channel_head)
3541 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
3543 /* Get buffer space */
3544 buffer = GCT_get_connections_buffer (t);
3550 /* Count and remember choked channels */
3552 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3554 if (GNUNET_NO == get_channel_allowed (iter))
3556 choked[choked_n++] = iter->ch;
3560 /* Unchoke random channels */
3561 while (0 < buffer && 0 < choked_n)
3563 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3565 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3568 choked[r] = choked[choked_n];
3574 * Send ACK on one or more connections due to buffer space to the client.
3576 * Iterates all connections of the tunnel and sends ACKs appropriately.
3581 GCT_send_connection_acks (struct CadetTunnel *t)
3583 struct CadetTConnection *iter;
3586 uint32_t allow_per_connection;
3588 unsigned int buffer;
3590 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3599 if (CADET_TUNNEL_READY != t->cstate)
3602 buffer = GCT_get_channels_buffer (t);
3603 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3605 /* Count connections, how many messages are already allowed */
3606 cs = GCT_count_connections (t);
3607 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3609 allowed += get_connection_allowed (iter);
3611 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3613 /* Make sure there is no overflow */
3614 if (allowed > buffer)
3617 /* Authorize connections to send more data */
3618 to_allow = buffer - allowed;
3620 for (iter = t->connection_head;
3621 NULL != iter && to_allow > 0;
3624 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3625 || get_connection_allowed (iter) > 64 / 3)
3629 allow_per_connection = to_allow/cs;
3630 to_allow -= allow_per_connection;
3632 GCC_allow (iter->c, allow_per_connection,
3633 GCC_is_origin (iter->c, GNUNET_NO));
3638 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3639 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3645 * Cancel a previously sent message while it's in the queue.
3647 * ONLY can be called before the continuation given to the send function
3648 * is called. Once the continuation is called, the message is no longer in the
3651 * @param q Handle to the queue.
3654 GCT_cancel (struct CadetTunnelQueue *q)
3659 /* tun_message_sent() will be called and free q */
3661 else if (NULL != q->tqd)
3663 unqueue_data (q->tqd);
3665 if (NULL != q->cont)
3666 q->cont (q->cont_cls, NULL, q, 0, 0);
3677 * Sends an already built message on a tunnel, encrypting it and
3678 * choosing the best connection if not provided.
3680 * @param message Message to send. Function modifies it.
3681 * @param t Tunnel on which this message is transmitted.
3682 * @param c Connection to use (autoselect if NULL).
3683 * @param force Force the tunnel to take the message (buffer overfill).
3684 * @param cont Continuation to call once message is really sent.
3685 * @param cont_cls Closure for @c cont.
3687 * @return Handle to cancel message. NULL if @c cont is NULL.
3689 struct CadetTunnelQueue *
3690 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3691 struct CadetTunnel *t, struct CadetConnection *c,
3692 int force, GCT_sent cont, void *cont_cls)
3694 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3699 * Send an Axolotl KX message.
3701 * @param t Tunnel on which to send it.
3704 GCT_send_ax_kx (struct CadetTunnel *t)
3706 struct GNUNET_CADET_AX_KX msg;
3708 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
3710 msg.header.size = htons (sizeof (msg));
3711 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
3712 msg.permanent_key = ax_identity.permanent_key;
3713 msg.purpose = ax_identity.purpose;
3714 msg.signature = ax_identity.signature;
3715 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
3716 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
3718 t->ephm_h = send_kx (t, &msg.header);
3719 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
3724 * Sends an already built and encrypted message on a tunnel, choosing the best
3725 * connection. Useful for re-queueing messages queued on a destroyed connection.
3727 * @param message Message to send. Function modifies it.
3728 * @param t Tunnel on which this message is transmitted.
3731 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3732 struct CadetTunnel *t)
3734 struct CadetConnection *c;
3737 c = tunnel_get_connection (t);
3740 /* TODO queue in tunnel, marked as encrypted */
3741 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3744 fwd = GCC_is_origin (c, GNUNET_YES);
3745 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3746 GNUNET_YES, NULL, NULL));
3751 * Is the tunnel directed towards the local peer?
3755 * @return #GNUNET_YES if it is loopback.
3758 GCT_is_loopback (const struct CadetTunnel *t)
3760 return (myid == GCP_get_short_id (t->peer));
3765 * Is the tunnel this path already?
3770 * @return #GNUNET_YES a connection uses this path.
3773 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3775 struct CadetTConnection *iter;
3777 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3778 if (path_equivalent (GCC_get_path (iter->c), p))
3786 * Get a cost of a path for a tunnel considering existing connections.
3789 * @param path Candidate path.
3791 * @return Cost of the path (path length + number of overlapping nodes)
3794 GCT_get_path_cost (const struct CadetTunnel *t,
3795 const struct CadetPeerPath *path)
3797 struct CadetTConnection *iter;
3798 const struct CadetPeerPath *aux;
3799 unsigned int overlap;
3807 GNUNET_assert (NULL != t);
3809 for (i = 0; i < path->length; i++)
3811 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3813 aux = GCC_get_path (iter->c);
3817 for (j = 0; j < aux->length; j++)
3819 if (path->peers[i] == aux->peers[j])
3827 return path->length + overlap;
3832 * Get the static string for the peer this tunnel is directed.
3836 * @return Static string the destination peer's ID.
3839 GCT_2s (const struct CadetTunnel *t)
3844 return GCP_2s (t->peer);
3848 /******************************************************************************/
3849 /***************************** INFO/DEBUG *******************************/
3850 /******************************************************************************/
3853 * Log all possible info about the tunnel state.
3855 * @param t Tunnel to debug.
3856 * @param level Debug level to use.
3859 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3861 struct CadetTChannel *iterch;
3862 struct CadetTConnection *iterc;
3865 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3867 __FILE__, __FUNCTION__, __LINE__);
3871 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3872 LOG2 (level, "TTT cstate %s, estate %s\n",
3873 cstate2s (t->cstate), estate2s (t->estate));
3874 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3875 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3876 #if DUMP_KEYS_TO_STDERR
3877 LOG2 (level, "TTT my EPHM\t %s\n",
3878 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
3879 LOG2 (level, "TTT peers EPHM:\t %s\n",
3880 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3881 LOG2 (level, "TTT ENC key:\t %s\n",
3882 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3883 LOG2 (level, "TTT DEC key:\t %s\n",
3884 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3887 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3888 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3889 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3890 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3893 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3894 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3896 LOG2 (level, "TTT channels:\n");
3897 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3899 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3902 LOG2 (level, "TTT connections:\n");
3903 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3905 GCC_debug (iterc->c, level);
3908 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3913 * Iterate all tunnels.
3915 * @param iter Iterator.
3916 * @param cls Closure for @c iter.
3919 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3921 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3926 * Count all tunnels.
3928 * @return Number of tunnels to remote peers kept by this peer.
3931 GCT_count_all (void)
3933 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3938 * Iterate all connections of a tunnel.
3940 * @param t Tunnel whose connections to iterate.
3941 * @param iter Iterator.
3942 * @param cls Closure for @c iter.
3945 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3947 struct CadetTConnection *ct;
3949 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3955 * Iterate all channels of a tunnel.
3957 * @param t Tunnel whose channels to iterate.
3958 * @param iter Iterator.
3959 * @param cls Closure for @c iter.
3962 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3964 struct CadetTChannel *cht;
3966 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3967 iter (cls, cht->ch);